feat: inline tool display and thinking/reasoning support

- Tool calls now appear at their stream position within messages (ContentSegment model)
- Added reasoning/thinking display: collapsible <details> block above content
- Set DeepSeek V4 Flash reasoningEffort to max via providerOptions
- ChatMessage.content changed from string to ContentSegment[] (text | tool-call)
- Agent handles AI SDK reasoning events, yields reasoning-delta
- Fixed duplicate key in ChatMessage.svelte each block

2 files changed, 6 insertions, 0 deletions

diff --git a/packages/core/src/agent/agent.ts b/packages/core/src/agent/agent.ts
index c28d691..8e89bb9 100644
--- a/packages/core/src/agent/agent.ts
+++ b/packages/core/src/agent/agent.ts
@@ -80,6 +80,9 @@ export class Agent {
 				messages: toCoreMessages(this.messages),
 				tools: registry.getAISDKTools(),
 				maxSteps: 10,
+				providerOptions: {
+					openaiCompatible: { reasoningEffort: "max" },
+				},
 			});
 
 			let fullText = "";
@@ -90,6 +93,8 @@ export class Agent {
 				if (event.type === "text-delta") {
 					fullText += event.textDelta;
 					yield { type: "text-delta", delta: event.textDelta };
+				} else if (event.type === "reasoning") {
+					yield { type: "reasoning-delta", delta: event.textDelta };
 				} else if (event.type === "tool-call") {
 					const toolCall: ToolCall = {
 						id: event.toolCallId,
diff --git a/packages/core/src/types/index.ts b/packages/core/src/types/index.ts
index a408e7d..28e79ae 100644
--- a/packages/core/src/types/index.ts
+++ b/packages/core/src/types/index.ts
@@ -29,6 +29,7 @@ export type AgentStatus = "idle" | "running" | "error";
 export type AgentEvent =
 	| { type: "status"; status: AgentStatus }
 	| { type: "text-delta"; delta: string }
+	| { type: "reasoning-delta"; delta: string }
 	| { type: "tool-call"; toolCall: ToolCall }
 	| { type: "tool-result"; toolResult: ToolResult }
 	| { type: "error"; error: string }